1. Field of the Invention
The present invention relates to a sorter which stacks articles to be treated on receptacles, such as trays, during sorting, and then applies a treatment, such as stapling or bonding, to the articles. The article to be treated may include, for example, sheets discharged from photocopiers, printers or the like.
2. Description of the Prior Art
Generally, a sorter of this type, such as a sorter with a stapler, is provided with vertically movable trays. The trays are sequentially shifted to be placed in an open state for receiving a sheet. Sheets are stacked on tray bins in the open state in a sorted manner by discharging the sheets to them. After stacking of sheets are completed, the sheets on respective trays are stapled with the stapler.
To place each tray in the open state, such a conventional sorter is provided with a mechanism for vertically moving a tray away at one side thereof from an upper adjacent tray. In this manner, the sorter is capable of receiving a sheet in the tray from the moved away side without being prevented by the upper adjacent tray.
In conventional sorters, the tray to which a sheet is discharged is however not sufficiently moved away at the opposite sides thereof form the adjacent upper tray.
For this reason, it is not possible to provide sufficiently large sheet accommodation space to a tray when a sheet is discharged into the tray. Particularly, when a large amount of sheets are stacked, they are not smoothly received in trays. There is the same problem in a sorter with article receptacles which are operated in a fashion similar to such trays.